DE102013005858B3 - Method of lining boreholes for deep wells and apparatus for carrying out the method - Google Patents

Abstract

The invention relates to a method for lining boreholes for deep drilling. According to the invention, a lining process that enables a rapid workflow with a substantially constant borehole diameter is characterized in that the borehole (5) is lined with a hybrid material consisting of a fibrous material and a hardenable medium directly after drilling. The invention further relates to a device for carrying out the method.

Description

The invention relates to a method for lining boreholes for deep wells. Furthermore, the invention relates to a device for carrying out the method.

The creation of boreholes for vertical deep wells, that is holes that are driven into a depth of over 500 m in the ground, takes place in practice according to the so-called Rotary method in which by means of a rotating bit, the rock to be pierced schabend crushed is continuously discharged through a flushing liquid, which is pumped down through the drill pipe.

For very deep wells usually a drilling turbine is used, which is located directly above the drill bit. The drill string adjoining the drill bit counter to the drilling direction does not rotate with the drill bit in this method, but only serves for the bit feed and the supply of the rinsing liquid.

Drill bits with diamond or tungsten carbide fillings have a shelf life of 70 to 100 hours under normal soil conditions. Then, to replace and refurbish the drill bit, the entire drill string must be pulled out of the wellbore and disassembled to subsequently be lowered back into the wellbore with the new drill bit. Thus, in the conventional deep drilling method results in a discontinuous course of the drilling process.

To prevent the wellbore from collapsing, the wellbore must be supported, which is done by conventional tubing drilling. This is done in stages with decreasing pipe diameter such that, for example, at a depth of 3000 m deep oil well, a first reaching to a depth of 5 m pipe with an outer diameter of 473 mm is introduced. After a drilling depth of 150 m, a casing or casing called a 340 mm outer diameter is pushed in to the bottom of the hole and the gap between the borehole wall and the casing is filled with cement slurry. At a drilling depth of 1500 m and a final depth of 3000 m, further casings with casing pipes each have a smaller outer diameter than the previous casing pipes, so that the outer diameter of the last casing after reaching the final depth is only 140 mm.

Although this known deep drilling method has proven itself in practice, the discontinuous lining or casing of the borehole wall is very time-consuming. In addition, the stepwise decreasing inner diameter of the borehole is not advantageous for all applications.

On this basis, the present invention seeks to provide a method for lining boreholes for deep wells that allows a fast workflow with a substantially constant diameter borehole.

The solution to this problem is inventively characterized in that the well is lined directly after drilling with a consisting of a pulp and a curable medium hybrid material.

The direct lining of the borehole according to the invention after boring with a fiber-reinforced hybrid material makes it possible for the first time to provide a continuous lining method, if the drilling process permits it, moreover a borehole lining with a substantially constant borehole diameter.

According to a practical embodiment of the invention it is proposed that the curable medium is sprayed onto the fiber material. The spray process ensures a uniform and rapid wetting of the fiber material with the hardenable medium.

To form this lining of the borehole wall serving hybrid material consisting of a reinforcing fiber and a thermosetting medium preferably carbon fibers and concrete are used. Depending on requirements, the lining of the borehole can be single-layered or multi-layered.

Of course, other fibrous materials and other thermosetting media, such as plastics, may be used to line the borehole as an alternative to the aforementioned carbon fibers and the concrete as a hardening medium.

A device according to the invention for carrying out the lining method according to the invention is characterized by a borehole lining module which has spray nozzles for applying a hardening medium and a reinforcing fabric laying device.

To secure the well as well as to shield the well to groundwater leading layers, the well is continuously lined directly after drilling. For this purpose, the Bohrlochauskleidemodul to spray nozzles Applying a hardening medium, such as concrete, and a Armierungsgewebeverlegevorrichtung. To form this lining of the borehole wall serving hybrid material consisting of a reinforcing fiber and a thermosetting medium preferably carbon fibers and concrete are used. The spreading of the fiber braid can be done via a cone, through which the reinforcing fiber can be applied directly to the borehole wall, in order to be subsequently wetted with the hardening medium can. Depending on requirements, the lining of the borehole can be single-layered or multi-layered.

Of course, other fibrous materials and other thermosetting media, such as plastics, may be used to line the borehole as an alternative to the aforementioned carbon fibers and the concrete as a hardening medium.

The supply of Bohrlochauskleidemoduls invention is advantageously via flexible pipe and / or hose lines over which the module is connected to utilities outside the borehole, wherein the pipe and / or hose lines for supplying and discharging the at least the Bohrlochauskleidemodul relevant materials and the supply of the serve electrical supply lines. Each individual line of this flexible pipe and / or hose lines is preferably designed as an endless line that can be kept ready on drums.

In the flexible tubing and / or tubing over which the downhole lining module is connected to out-of-well utilities, in addition to the electrical supply lines are also data lines, e.g. B. a bus system, via which at least the borehole lining module is connected to a working stand outside the borehole.

According to the invention, all environmental parameters in the borehole, such as temperature, pressure, rock density and the like, can be determined via the data lines in addition to the system parameters such as feed rate and pump pressure via sensors coupled to the data lines and can be transmitted to the workstation for controlling at least the borehole lining module.

Further features and advantages of the invention will become apparent from the accompanying drawings, in which an embodiment of a lining according to the invention is shown only by way of example, without limiting the invention to this embodiment. In the drawings shows:

1 a schematic side view of a drilling system according to the invention;

2 a front view of the drill head according to 1 and

3 a view according to 1 but showing the drilling system in a borehole.

1 shows a drilling system 1 for vertical deep drilling, essentially from a drill head 2 , a security module 3 and a borehole lining module 4 exists, with the individual assemblies 2 . 3 and 4 depending on the application, are arranged rigidly or relative to each other movable one behind the other.

Although it is called vertical deep drilling, it is with the method described below and drilling system 1 It is also possible to control the course of drilling from the vertical to a horizontal course, if necessary. The main direction of drilling is the deep vertical hole.

As from the in 3 illustrated arrangement of the in a borehole 5 arranged drilling system 1 it can be seen, the supply of the out of the drill head 2 , the security module 3 and the borehole lining module 4 existing drilling system 1 via flexible pipe and / or hose lines 6 about which the drilling system 1 with utilities 7 outside the borehole 5 connected is. The pipe and / or hose lines 6 For the supply and removal of the drilling system 1 relevant materials and to supply the electrical supply lines are the individual pipe and / or hose lines 6 designed as an endless line that can be kept on drums.

The individual pipe and / or hose lines 6 are connected at intervals with spacers and thus form a supply line leading into the borehole 5 to be led. To the tensile forces caused by the weight of the pipe and / or hose lines 6 and the weight of the drilling system 1 To be able to absorb, steel cables are preferably carried outside the borehole 5 are stored accordingly. Furthermore, there is the possibility of floats on the pipe and / or hose lines 6 determine the tensile load, since the borehole 5 is under water during the drilling process.

In the following, the drilling method and the borehole lining method are described by means of a chisel-free drilling method in which the drill head 2 is designed so that with this both high pressure water jet cutting as well to high-frequency rock smash is feasible.

However, the described Rohrlochauskleidideverfahren is independent of the operation of the drill head 2 , The decisive factor is that the lining process can be carried out directly after drilling.

How out 2 can be seen on the front face of the drill head 2 Water outlet nozzles 8th for high-pressure waterjet cutting and sonotrodes 9 arranged for the transmission of high-frequency vibrations for the high-frequency rock fragmentation.

In order to ensure a uniform and substantially full-surface machining of the rock to be drilled over the entire borehole diameter, the entire boring head 2 , but at least one with the water outlet nozzles 8th as well as the sonotrodes 9 provided face plate 10 of the drill head 2 formed rotatable about the central axis.

For sucking the drilling mud arising during the drilling process are in the face plate 10 suction 17 provided, sucked through the drilling mud and through the pipe and / or hose lines 6 from the borehole 5 can be pumped.

To generate the high-frequency pulses for the high-frequency Steinzertrümmerung piezo elements in the drill head 2 arranged, each with one from a sonotrode 9 and an amplification transformer existing amplification unit are coupled. To the sonotrodes 9 To protect against wear, these are advantageously coated, for example with polycrystalline diamond.

The pumps for high-pressure water jet cutting as well as for the aspiration of the flushing medium are on the drill head 2 and / or on the security module 3 arranged. In order to increase the cutting action of the high pressure water jet, an abrasive such as quartz sand may be added to the water jet such that the drill head 2 over the flexible pipe and / or hose lines 6 fed and only in the water outlet nozzle 8th mixed with the water jet to minimize wear on the lines. The addition of the abrasive can be done continuously or only temporarily.

By combining the high-pressure water jet cutting with the high-frequency rock smashing, as well as by the surface formation of the drill head 2 and the corresponding placement of the water outlet nozzles 8th and sonotrodes 9 For example, in the illustrated embodiment, it is possible to perform the drilling operation continuously, that is, without interruption to the refurbishment of a drill bit or to remove a cutaway drill core, as is required in the prior art deep hole drilling method.

In order to use a continuous drilling method as efficiently as possible, it is advantageous, albeit the securing and lining of the borehole 5 can be essentially continuous.

To secure the borehole 5 as well as for shielding the borehole leading to groundwater layers becomes the borehole 5 lined right after drilling. For this purpose, the borehole lining module according to the invention 4 spray nozzles 11 for applying a hardening medium, such as concrete, and a reinforcing fabric laying apparatus 12 on.

Preferably, carbon fibers and concrete are used to make the borehole lining lining, but other fiber materials and other hardening media, such as plastics, may also be used to make the hybrid material.

The reinforcing fabric laying device 12 for applying the fiber braid can be done for example via a cone over which the reinforcing fiber can be applied directly to the borehole wall, in order to be subsequently wetted with the hardening medium can. Depending on depth and geological conditions may be the lining of the borehole 5 single or multi-layered. By adding special additives, the curing time of the concrete can be accelerated. In deeper regions with a higher earth temperature, the hardening time is shortened by the temperature rise alone. The mixing of the over the pipe and / or hose lines 6 fed concrete with the also on the pipe and / or hose lines 6 supplied additives takes place only at the Borlochauskleidemodul 4 to prevent hardening in the supply lines.

A finished borehole lining 18 is schematic in 3 shown.

The security module 3 is used in case of a sudden increase in pressure in the borehole 5 For example, by the drilling of a gas bubble, on the one hand uncontrolled leakage of the gas from the wellbore 5 prevent and on the other hand prevent the entire drilling system 1 by the pressure increase upwards from the borehole 5 can be pushed. This is indicated by the security module 3 at least one blocking element 13 for the positive closing of the bore hole inside diameter and clamping elements 14 for non-positive fixing of the drilling system 1 in the borehole 2 on.

The positive locking of the borehole diameter over the blocking element 13 can be done, for example, with an expander ring, the borehole 5 closes in order to reduce the pressure then controlled by suitable pressure valves can. The clamping elements 14 that make up the entire drilling system 1 non-positively in the borehole 5 can dig, for example, are designed as radially upwardly and outwardly facing barbs that the drilling system 1 if necessary in the respective position in the borehole 5 fix.

The drive and the steering and control device for the drill head 2 are at the drill head 2 arranged. In the illustrated embodiment, the drive for the drill head 2 as on the outside of the drill head 2 arranged caterpillar drive 15 educated.

In the flexible pipe and / or hose lines 6 about which the drilling system 1 with utilities 7 outside the borehole 5 is connected, in addition to the electrical supply lines and data lines, z. B. a bus system through which the drill head 2 and / or the security module 3 and / or the borehole lining module 4 with a working status 16 outside the borehole 5 are connected.

In addition to the system parameters, such as, for example, feed rate and pump pressure, sensors that are coupled to the data lines via these data lines contain all environmental parameters in the borehole 5 , such as temperature, pressure, rock density and the like, can be determined and used to control the drilling system 1 to the work status 16 transmittable.

As in the illustrated drilling system 1 in particular the drill head 2 a larger outer diameter than the finished lined hole 5 , the complete drilling system remains 1 after completion of drilling in the borehole 5 and, after capping the supply lines via the existing data lines for data exchange with the work status 16 be used.

Should an alternative drilling method or use of an alternative bit make it necessary to remove it from the hole in the meantime or at the end of the drilling process 5 is removed, so this alternative drill head, for example, be designed to be foldable so that its outer diameter is reduced so that it passes through the finished well casing 18 is movable.

The control of the drilling system 1 can drill on just one of the components 2 , Security module 3 or borehole lining module 4 or distributed over several of the components 2 . 3 and 4 be arranged.

The borehole lining method described above, which can be used for geothermal wells as well as for the development of natural gas or crude oil deposits, is characterized in that a quasi-continuous lining of the borehole directly after drilling is possible. In addition, the borehole lining points 18 over the entire borehole length a substantially constant cross section.

LIST OF REFERENCE NUMBERS

1

Drilling System

2

wellhead

3

security module

4

Bohrlochauskleidemodul

5

well

6

Pipe and / or hose line

7

supply

8th

water outlet

9

sonotrode

10

faceplate

11

nozzle

12

Armierungsgewebeverlegevorrichtung

13

blocking element

14

clamping element

15

Track drive

16

working status

17

suction

18

well casing

Claims (9)

Method for lining boreholes for deep boreholes, characterized in that the borehole ( 5 ) is lined directly after drilling with a hybrid material consisting of a pulp and a curable medium, wherein in a first step, the pulp is applied directly to the borehole wall, and wherein in a second step, the pulp is wetted with the curable medium. Method according to claim 1, characterized in that the wall of the borehole ( 5 ) is lined continuously. A method according to claim 1 or 2, characterized in that the curable medium is sprayed onto the fiber material. Method according to one of claims 1 to 3, characterized in that the hybrid material is applied to the borehole wall in one or more layers. Device for carrying out the method according to one of claims 1 to 4, characterized by a borehole lining module ( 4 ), the spray nozzles ( 11 ) for applying a hardening medium and a reinforcing fabric laying device ( 12 ) having. Apparatus according to claim 5, characterized in that the borehole lining module ( 4 ) via flexible pipe and / or hose lines ( 6 ) with utilities ( 7 ) outside the borehole ( 5 ), wherein the pipe and / or hose lines ( 6 ) for the supply and removal of the borehole lining module ( 4 ) materials and serve for the supply of electrical supply lines. Apparatus according to claim 5 or 6, characterized in that the borehole lining module ( 4 ) via data lines with a working status ( 16 ) outside the borehole ( 5 ) connected is. Apparatus according to claim 7, characterized in that the data lines are a bus system. Apparatus according to claim 7 or 8, characterized in that in addition to the system parameters via sensors coupled to the data lines via the data lines all environmental parameters in the borehole ( 5 ) and for controlling the borehole lining module ( 4 ) to the work status ( 16 ) are transferable.

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